The electrochemical detection of droplets in microfluidic devices.
This paper presents a new electrochemical method for the detection and characterisation of aqueous droplets in an organic carrier fluid (1,2-dichloroethane) formed in flow-focusing microfluidic devices. The devices consist of a conventional flow-focusing channel 250 microm wide and 250 microm deep cast out of poly(dimethylsiloxane) (PDMS) which is sealed onto a glass substrate containing a set of microelectrodes 100 microm long. Chronoamperometric analysis of a suitable electrolyte contained in the organic phase is presented for characterising the droplet frequency and size. This chronoamperometric method is then extended to a dual working electrode approach in order to determine the velocity of the droplet. Good agreement between experimental measurements and theory was observed.
Liu
Shujuan
S
Department of Chemical Engineering, University of Cambridge, Cambridge, UKCB2 3RA.
Gu
Yunfeng
Y
Le Roux
Rudolph B
RB
Matthews
Sinéad M
SM
Bratton
Daniel
D
Yunus
Kamran
K
Fisher
Adrian C
AC
Huck
Wilhelm T S
WT
D003365:Costs and Cost Analysis; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004563:Electrochemistry; D004581:Electronics; D005898:Glass / Q000737:chemistry; D008839:Microelectrodes; D044085:Microfluidics / Q000191:economics / Q000379:methods*; D055620:Optical Phenomena
D004129:Dimethylpolysiloxanes; C013830:baysilon